System Description

The computerized engine control system is built around a Single Board Engine Controller (SBEC II). The SBEC II monitors up to 22 inputs and responds with appropriate outputs to manage fuel delivery, ignition timing, and emission control devices, charging system, speed control and idle speed. The engine controller is a pre-programmed, dual microprocessor digital computer. As operating conditions change, the SBEC II adjusts injector pulse width and ignition timing for optimum performance and fuel economy.
The Multi-Point Fuel Injection System (MPFI) controls fuel delivery. Fuel is injected into the intake manifold before the intake valve in precise amounts through electrically operated injectors. The injectors are fired in a specific sequence by the SBEC II. The SBEC II constantly adjusts the amount of fuel injected to meet changing operating conditions by controlling injector pulse width (the length of time the injector is energized).
The SBEC II also adjusts the ignition timing by controlling the ignition coil dwell.


SBEC II INPUTS

^ Start Signal
^ Engine Coolant Temperature
^ Intake Manifold Air-Fuel Temperature
^ Intake Manifold Absolute Pressure
^ Engine Speed (crankshaft position)
^ Throttle Position
^ Exhaust Gas Oxygen Content
^ Battery Voltage
^ A/C Request Predict
^ Instrument Panel A/C Select Switch
^ Wide Open Throttle Switch
^ Closed Throttle Switch
^ Neutral Safety Switch
^ Power Steering Switch
^ Alternator output
^ Brake Switch
^ Ignition circuit sense (run position)
^ Overdrive Override Solenoid
^ Park/Neutral Switch
^ SCI receive (DRB II connection)
^ Speed Control Resume Switch
^ Speed Control Set Switch
^ Speed Control On/Off Switch
^ Sync Signal
^ Vehicle distance (speed) sensor



SBEC II OUTPUTS

^ Electric Fuel Pump Relay
^ Alternator Field
^ Ballast Bypass
^ Check Engine Lamp
^ Ignition Coil
^ Fuel Injectors
^ Radiator Fan Relay
^ SCI Transmit (DRB II Connection)
^ Shift Indicator Lamp
^ Emission Maintenance Reminder (EMR) Lamp
^ Speed Control Vacuum Solenoid
^ Speed Control Vent Solenoid
^ Tachometer

NOTE: Not all models use all inputs and outputs